1. Technical Field
The present invention relates to a printing apparatus arranged in such a way as to print a predetermined letter and image by ejecting minuscule droplets of liquid from a plurality of nozzles, and forming their microscopic particles (dots) on a printing medium.
2. Related Art
An ink jet printer which is one of printing apparatus of this kind, as it is possible therewith to easily obtain a generally inexpensive and high-quality color print, has come into widespread use among not only offices but also general users, along with a prevalence of a personal computer, a digital camera and the like.
Meanwhile, in the printing apparatus, a failure to convey a printing medium, that is, a so-called paper jam, becomes problematic. Therein, in a printing apparatus described in JP-A-2000-203009, an arrangement is such that, a spur which presses the printing medium being provided on a side of liquid ejection heads, a rotational condition of the spur is detected by an encoder, the printing medium conveyance failure is detected from the rotational condition and, in the event that the printing medium conveyance failure is detected, a rotational drive of a drive motor for a conveyor belt is stopped so as to stop the conveyor belt. Also, in an image forming apparatus described in JP-A-10-265089, an arrangement is such that, in the event that the printing medium conveyance failure is detected, the conveyor belt is stopped by moving one gear of a train of gears of a drive system for the conveyor belt in such a way that the gear is pulled out of the train of gears.
However, in the printing apparatus described in JP-A-2000-203009, as the arrangement is such that the rotational drive of the drive motor is stopped so as to stop the conveyor belt, the large-inertia drive system and drive motor remain connected to the conveyor belt and, even in the event that a friction element, such as a brake, is used as a stopping aid, it is impossible to stop the conveyor belt within a short time. For example, in a line head ink jet printer, as one-pass printing is possible, high-speed printing is carried out and, unless the conveyor belt can be stopped within the short time, the printing medium, which has failed to stop completely and been conveyed to a printing area, hits the liquid ejection heads, or is caught in a gap between the conveyor belt and the liquid ejection heads. As opposed to this, in the image forming apparatus described in JP-A-10-265089, as one gear is pulled out of the train of gears of the drive system, the large-inertia drive motor being cut off from the conveyor belt, it is possible to stop the conveyor belt within a short time. However, in the event that the gear is pulled out of the train of gears, when the gear pulled out is inserted into the train of gears after fixing the paper jam, there is a fear of teeth of the gears interfering with each other and wearing down.